Method and system for photoselective vaporization for gynecological treatments

ABSTRACT

A method for photoselective vaporization of uterine tissue includes delivering laser radiation to the treatment area on the tissue, via an optical fiber for example, wherein the laser radiation has a wavelength and irradiance in the treatment area on the surface of the tissue sufficient because vaporization of a substantially greater volume of tissue than a volume of residual coagulated tissue caused by the laser radiation. The laser radiation is generated using a neodymium doped solid-state laser, including optics producing a second or higher harmonic output with greater than 60 watts average output power. The delivered laser radiation has a wavelength for example in a range of about 200 run to about 650 nm, and has an average irradiance in the treatment area greater than about 10 kilowatts/cm 2 , in a spot size of at least 0.05 mm 2 .

RELATED APPLICATION INFORMATION

[0001] The present invention claims the benefit of U.S. ProvisionalApplication No. 60/358,356, entitled METHOD FOR TREATMENT OFGYNECOLOGICAL CONDITIONS USING A HIGH POWER LASER IN CONJUCTION WITH AHYSTEROSCOPE, filed 22 Feb. 2002.

[0002] The present application is related to, and incorporates byreference as if fully set forth herein, U.S. patent application Ser. No.10/278,723, entitled METHOD AND SYSTEM FOR PHOTOSELECTIVE VAPORIZATIONOF THE PROSTATE, AND OTHER TISSUE, filed 23 Oct. 2002;

[0003] U.S. patent application Ser. No. 09/737,721, entitled METHODS FORLASER TREATMENT OF SOFT TISSUE, filed 15 Dec. 2000; and

[0004] U.S. patent application Ser. No. 10/279,087, entitled METHOD ANDSYSTEM FOR TREATMENT OF BENIGN PROSTATIC HYPERTROPHY (BPH), invented byMurray, et al.; filed: 23 Oct. 2002

BACKGROUND OF THE INVENTION

[0005] 1. Field of the Invention

[0006] The present invention relates generally to laser treatment oftissue, and more particularly to photoselective vaporization of tissue,including uterine tissue, as applied to the treatment of gynecologicalconditions.

[0007] 2. Description of Related Art

[0008] A commonly employed procedure for removal of tissue in thetreatment of gynecological conditions involves the use of a hysteroscopeand a small wire loop energized by radio frequency energy to cut tissue.

[0009] Nd:YAG lasers delivering output with a wavelength of 1064 nm havebeen used for the treatment of gynecological conditions such as theablation of the endometrium. Although 1064 nm light is hemostatic athigh power levels, its low absorption in blood and uterine tissue leadsto inefficient ablation and a large residual layer of thermallydenatured tissue several millimeters thick.

[0010] High power densities are required for rapid and efficientvaporization of tissue. The difficulty of achieving higher averageoutput power densities is that when high input powers are supplied tothe laser element from an excitation source such as an arclamp a largeamount of heat is generated in the lasing element. This heat inducesvarious deleterious effects in the lasing element. In particular thetemperature difference between the coolant and the hot lasing elementgenerates a thermally induced graded index lens that decreases the beamquality of the laser and causes the laser to operate with moretransverse optical modes than it would otherwise.

[0011] The M² parameter is a well established convention for definingthe beam quality of a laser and is discussed in pages 480-482 of OrazioSvelto and David C. Hanna, Principles of Lasers, Plenum Press, New York,1998, which is incorporated herein by reference. The beam qualitymeasures the degree to which the intensity distribution is Guassian. Thequantity M² is sometimes called inverse beam quality rather than beamquality but in this application it will be referred to as beam quality.M² is defined as${{M_{x}^{2} \equiv \frac{\left( {\sigma_{x}\sigma_{f}} \right)_{NG}}{\left( {\sigma_{x}\sigma_{f}} \right)_{G}}} = {4\quad {\pi \left( {\sigma_{x}\sigma_{f}} \right)}_{NG}}},$

[0012] where π refers to the number 3.14 . . . , σ is used to representthe spot size, the subscripts x and f represent the spatial andfrequency domains along the x-axis, respectively, and the subscripts Gand NG signify Guassian and non-Guassian, respectively. The x-axis istransverse to the direction of propagation of the beam. The beam qualityin any direction transverse to the beam may be essentially the same.Therefore the subscript x is dropped from the M² elsewhere in thespecification. The beam widths or σs are determined based on thestandard deviation of the position, where the squared deviation of eachposition is weighted by the intensity at that point. The beam width inthe frequency domain σ_(f) is the beam width of the beam after beingFourier transformed.

[0013] The formula usually used for calculating the angular divergence,θ, of a beam of light of wavelength λ is strictly valid only for a beamhaving a Guassian intensity distribution. The concept of beam qualityfacilitates the derivation of the angular divergence, θ, for the beamwith a non-Guassian intensity distribution, according to$\theta = {{M^{2}\left( \frac{2\quad \lambda}{\pi \quad \sigma_{x}} \right)}.}$

[0014] For example, a TEM00 laser beam has a high beam quality with anM² of 1, whereas by comparison, high power surgical lasers operate withM² values greater than 100.

[0015] The Applicants have recognized that high power lasers typicallyhave an M²>144. The larger number of modes makes M² larger and makes itdifficult to focus the light into small, low numerical aperture fibersand reduces the ability to project high power density light onto tissue.As a result, the vaporization efficiency of CW arclamp pumped 532 nmlasers is significantly reduced.

[0016] Surgical procedures within the uterus have unique risks. Forexample, precision surgery is of high importance for patients who wantto maintain their fertility. Any surgery in the uterus must avoidweakening of the wall of the uterus, which could lead to complicationsduring pregnancy. Also, the physiological diversity of the uterusincreases the difficulty of intrauterine operations. The cornual areasof the uterus represent a vulnerable portion of the uterus. In case of amyoma in the cornu, the uterine wall is further thinned by the myoma,which increases the risk of intraoperative perforation of the uterinewall. Even if perforation does not occur, the presence of a thin uterinewall could predispose the patient to bowel injury. As stated by Indman,J. Reproduct. Med. 1991, lack of precise knowledge of the minimumthickness of the uterine wall may be the limiting factor in determiningthe safety of use of the 1064 nm Nd:YAG laser for endometrial ablation.

SUMMARY OF THE INVENTION

[0017] Photoselective vaporization of tissue, such as tissue subject ofremoval for treatment of gynecological conditions, is based uponapplying a high intensity radiation to tissue using a radiation that ishighly absorptive in the tissue, while being absorbed only to anegligible degree by water or other irrigant during the operation, atpower densities such that the majority of the energy is converted tovaporization of the tissue without significant residual coagulation ofadjacent tissue.

[0018] The present invention provides a method for treating gynecologicconditions, including conditions involving uterine tissue, such asintramural and intracavitery uterine myomas, leiomyoma uteri,rhabdomyoma, endometriosis, endometrial hyperplasia, endometrial cysts,endometrial polyps, menorrhagia, uterine septa, intrauterine adhesions,or cervical intraepithelial neoplasia. Other gynecological conditionsinvolving the female reproductive organs such as the fallopian tubes,the ovaries, and the vagina, are also treatable according to the presentinvention. Treatment according to the embodiments of present inventionis executed by vaporizing, incising, or coagulating tissue, such asuterine tissue, using a laser that generates light with an average powergreater than 40 watts and a wavelength between 300 and 700 nm where theoutput beam of the laser is delivered to the target tissue through anoptical waveguide, such as an optical fiber that emits light in forwarddirection (end-firing) or in a laterally directed manner (side-firing)where laterally means at an angle of 10°-170° with respect to the fiberaxis, and where the waveguide is guided into the vagina or the uterinecavity using a hysteroscope. In embodiments of the invention, thehysteroscope is equipped with a rigid tip. In other embodiments of theinvention, the hysteroscope is equipped with a flexible tip, which canbe manipulated by the surgeon, allowing greater control over theprocedure, and access to more regions of the target tissue.

[0019] In other embodiments, the wavelength of the delivered radiationis between 1100 and 1800 nm, or in other bands that are efficientlyabsorbed by the target tissue.

[0020] Yet other embodiments employ a laser system, that generates lightof two wavelengths, with for example two lasers arranged to providelight to a beam delivery system, with the light of the first wavelengthhaving an average power greater than 40 watts, and in some embodimentsmore than 60 Watts, and a wavelength between 300 and 700 nm, such as awavelength of 532 nm, and the light of the second wavelength having awavelength of 1064 nm. In alternative one or two wavelength systems,delivered light is between 1100 and 1800 nm.

[0021] According to one embodiment of the invention, a method fortreating gynecological conditions comprises the steps of providing asolid-state laser having a laser element positioned to receive pumpradiation from an excitation source; in some cases modulating the sourceto cause the laser to emit pulsed laser light; and delivering the laserlight to targeted tissue. Various solid-state lasers may be used forthis purpose, including (without limitation), a Q-switched laser using afrequency doubling crystal such as potassium-titanyl-phosphate (KTP),pumped using a diode array, an arc lamp or a flash lamp. WhileQ-switching induces short, “micro-pulses,” a “macro-pulse” duration ofthe laser light is preferably in the range of 0.1 to 500 milliseconds,induced by for example modulating the pump energy with the desiredmacro-pulse length. The wavelength of the laser light is preferablybetween 200 and 1000 nm, and more preferably between about 300 and 700nm. The laser light is preferably delivered to the targeted tissuethrough an optical fiber terminating at or near a distal end in aside-firing or end-firing probe.

[0022] Operation of the solid-state laser in a “macro-pulsed” mode ismore efficient in vaporizing tissue than a CW laser of the same averagepower. This is in part because the heat generated in a superficialtissue layer, which depth is defined by the optical penetration depth ofthe laser beam, doesn't have time to significantly diffuse into deepertissue layers during each macro pulse. The heat stays confined in thesuperficial tissue layer and leads to a rapid heating of the tissue tothe boiling point of water. The thermal energy generated within a tissuevolume has to exceed the vaporization enthalpy of water to fullyvaporize the tissue. For a laser operated in a macro-pulsed mode thiscondition is met for a larger tissue volume than for a laser operated ina continuous mode. The macro-pulsed laser is also more efficient and hashigher beam quality, with M2 values typically less than 144, than acontinuous wave laser with same average output power. The higher beamquality allows for higher irradiances on the tissue and thus a morerapid tissue vaporization.

[0023] According to a second embodiment of the invention, a method fortreating uterine tissue comprises the steps of providing a solid-statelaser having a laser element positioned to receive pump radiation from apump radiation source; modulating the pump radiation source to cause thelaser element to emit laser light having a pulse duration of between 0.1milliseconds and 500 milliseconds and an average output power exceeding20 watts; and delivering the laser light to targeted tissue.

[0024] According to a third embodiment of the invention, a method fortreating gynecological conditions comprises the steps of providing asolid-state laser having a laser element positioned to receive pumpradiation from a pump radiation source; Q-switching the laser togenerate a quasi-continuous wave (CW) beam having an average outputpower exceeding 60 watts; and, delivering the beam to targeted tissue.

[0025] According to a fourth embodiment of the invention, a method fortreating gynecological conditions comprises the steps of providing asolid-state laser having a laser element positioned to receive pumpradiation from a pump radiation source such as a laser diode;Q-switching the laser to generate a quasi-continuous wave (CW) beamhaving an average output power exceeding 20 watts with an M² less than144; and delivering the beam to uterine tissue.

[0026] It has been recognized that as more and more laser energy isconsumed by vaporization of the tissue, the amount of laser energyleading to residual tissue coagulation gets smaller, i.e. the amount ofresidual coagulation drops, and the side effects attendant to theresidual injury caused by the surgery drop dramatically. Thus, theextent of the zone of thermal damage characterized by tissue coagulationleft after the procedure gets smaller with increasing volumetric powerdensity, while the rate of vaporization increases. Substantial andsurprising improvement in results is achieved. It has been recognizedthat increasing the volumetric power density absorbed in the tissue tobe ablated, has the result of decreasing the extent of residual injuryof the surrounding tissue. This recognition leads to the use of higherpower laser systems, with greater levels of irradiance at the treatmentarea on the tissue, while achieving the lower levels of adverse sideeffects and a quicker operation times.

[0027] Although the invention can be generalized other types of tissue,one embodiment of the invention provides a method for photoselectivevaporization of uterine tissue, including for example the endometriumand myomas in the uterine wall. According to this embodiment, the methodincludes delivering laser radiation to the treatment area on the tissue,via an optical fiber for example, wherein the laser radiation has awavelength and irradiance in the treatment area on the surface of thetissue sufficient because vaporization of a substantially greater volumeof tissue than a volume of residual coagulated tissue caused by thelaser radiation. In one embodiment, the laser radiation is generatedusing a neodymium doped solid-state laser, including optics producing asecond or higher harmonic output with greater than 60 watts averageoutput power, and for example 80 watts average output power, or more.The laser radiation is coupled into an optical fiber adapted to directlaser radiation from the fiber to the treatment area on the surface ofthe tissue. For the treatment within the uterus, the fiber optic isinserted via hysteroscope, including lumens for delivering irrigants tothe treatment area, and for direct visualization during the treatment.For treatment in the uterine cornua, or other difficult to reachregions, and more generally because of physiological diversity in theuterus, a flexible tip hysteroscope is used in embodiments of thepresent invention.

[0028] In other embodiments, the delivered laser radiation has awavelength in a range of about 300 nm to about 700 nm, and has anaverage irradiance in the treatment area greater than about 10kilowatts/cm², in a spot size of at least 0.05 mm². More preferably, theirradiance is greater than about 20 kilowatts/cm², and even morepreferably greater than about 30 kilowatts/cm². The spot size inpreferred systems is for example less than about 0.8 mm².

[0029] Accordingly, in one embodiment, the second harmonic output of theneodymium dope solid-state laser is applied using an optical fiber witha flat tip for emitting radiation from the end, or with a side-firingtip. When using a side-firing tip, which causes a diverging beam to bedirected out of the optical fiber, the time is placed close to thetissue, within about 1 mm from the side of the side-firing tip tocontacting the side of the tip. Close placement increases the irradiancedelivered to the treatment area so that higher irradiance is availablewith solid-state lasers generating a 60 to 80 watts average outputpower.

[0030] According to the present invention, the efficiency of thevaporization and the reduction of injury to residual tissue aresufficient that the procedure may be carried out while applying lessanesthesia during the delivery of laser energy, and throughout theprocedure, than during other procedures. Anesthesia options for aprocedure according to the present invention include, but are notlimited to, paracervical block, and general or regional anesthesiatechniques.

[0031] Furthermore, embodiments of the invention include the delivery ofthe laser energy using a Q-switched, solid-state laser which producesmicro-pulses in combination with applying pump power to the laser mediumin a sequence a pulses so that output radiation is produced inmacro-pulses having a peak power of greater than 200 watts, and morepreferably about 240 watts or greater. The peak irradiance in thetreatment area during the pulses is thereby substantially increased, andpreferably greater than 50 kilowatts/cm², and as much as 90kilowatts/cm² in some embodiments of the invention.

[0032] Other aspects and advantages of the present invention can be seenon review the figures, the detailed description, and the claims whichfollow.

BRIEF DESCRIPTION OF THE DRAWINGS

[0033]FIG. 1 depicts a laser system for implementing the tissue ablationmethods of the invention;

[0034]FIG. 2 depicts a side-firing probe for use with the system of FIG.1;

[0035]FIG. 3 depicts an exemplary output waveform of the FIG. 1 laserwhen the laser is operated in a macro-pulsed mode; and

[0036]FIG. 4 depicts an exemplary output waveform of the FIG. 1 laserwhen the laser is operated in a quasi-CW mode.

[0037]FIG. 5 is a block diagram of a laser system adaptable for useaccording to the present invention.

[0038]FIG. 6 is a block diagram of an alternative laser system adaptablefor use according to the present invention.

[0039]FIG. 7 is a diagram of a flexible tip hysteroscope, adaptable foruse according to the present invention.

[0040]FIG. 8 illustrates absorption depth in tissue for 532 nm light.

[0041]FIG. 9 illustrates absorption depth in tissue for 1064 nm light.

[0042]FIG. 10 is a diagram of a beam path from an end view of a sidefiring tip, according to one embodiment of the present invention.

[0043]FIG. 11 is a diagram of a beam path from a side view of the sidefiring tip of FIG. 10, according to one embodiment of the presentinvention.

[0044]FIG. 12 is a heuristic diagram illustrating operation of thepresent invention.

[0045]FIG. 13 illustrates representative gynecological conditionstreatable according to the present invention.

[0046]FIG. 14 illustrates application of a side-firing probe on ahysteroscope for ablation of tissue in treatment of a protruding,intracavitery uterine myoma within the right uterine cornu.

[0047]FIG. 15 illustrates application of an end-firing probe on aflexible tip hysteroscope for ablation of tissue in treatment of aprotruding, intracavitery uterine myoma.

DETAILED DESCRIPTION

[0048]FIG. 1 is a block diagram depicting an exemplary laser system 100which may be employed for implementing the present invention. Lasersystem 100 includes a solid-state laser 102, which is used to generatelaser light for delivery through optical fiber 106 to target tissue 104.As will be discussed in further detail herein below, laser 102 iscapable of being operated in a “macro-pulsed” mode, wherein the laserlight is emitted as macro-pulses having relatively long pulse durations.

[0049] Laser 102 more specifically comprises a laser element assembly110, pump source 112, and frequency doubling crystal 122. In thepreferred embodiment, laser element 110 outputs 1064 nm light which isfocused into frequency doubling crystal 122 to create 532 nm light.According to one implementation, laser element assembly 110 may beneodymium doped YAG (Nd:YAG)crystal, which emits light having awavelength of 1064 nm (infrared light) when excited by pump source 112.Laser element 110 may alternatively be fabricated from any suitablematerial wherein transition and lanthanide metal ions are disposedwithin a crystalline host (such as YAG, Lithium Yttrium Fluoride,Sapphire, Alexandrite, Spinel, Yttrium Orthoaluminate, PotassiumGadolinium Tungstate, Yttrium Orthovandate, or Lanthanum ScandiumBorate). Laser element 110 is positioned proximal to pump source 112 andmay be arranged in parallel relation therewith, although othergeometries and configurations may be employed.

[0050] Pump source 112 may be any device or apparatus operable to excitelaser element assembly 110. Non-limiting examples of devices which maybe used as pump source 112, include: arc lamps, flashlamps, and laserdiodes.

[0051] A Q-switch 114 disposed within laser 102 may be operated in arepetitive mode to cause a train of micro-pulses to be generated bylaser 102. Typically the micro-pulses are less than 1 microsecond induration separated by about 40 microseconds, creating a quasi-continuouswave train. Q-switch 114 is preferably of the acousto-optic type, butmay alternatively comprise a mechanical device such as a rotating prismor aperture, an electro-optical device, or a saturable absorber.

[0052] Laser 102 is provided with a control system 116 for controllingand operating laser 102. Control system 116 will typically include acontrol processor which receives input from user controls (including butnot limited to a beam on/off control, a beam power control, and a pulseduration control) and processes the input to accordingly generate outputsignals for adjusting characteristics of the output beam to match theuser inputted values or conditions. With respect to pulse durationadjustment, control system 116 applies an output signal to a powersupply (not shown) driving pump source 112 which modulates the energysupplied thereto, in turn controlling the pulse duration of the outputbeam.

[0053] Although FIG. 1 shows a frequency doubled laser with anintracavity frequency doubling element, it is only by way of example.The infrared light can be internally or externally frequency doubledusing non-linear crystals such as KTP, Lithium Triborate (LBO), or BetaBarium Borate (BBO) to produce second harmonic 532 nm green light, andhigher harmonics. The frequency doubled, 532 nm wavelength and theshorter wavelength higher harmonic beams are better absorbed by thetissue, and promote more efficient tissue ablation.

[0054] In one preferred embodiment the resonant cavity control system isthat described in U.S. Pat. No. 5,151,909, which is incorporated byreference as if fully set forth herein.

[0055] Laser 102 further includes an output port couplable to opticalfiber 106. Output port 118 directs the light generated by laser 102 intooptical fiber 106 for delivery to tissue 104. Mirrors 124, 126, 128, and130 direct light from the lasing element 110 to the frequency doublingcrystal 122, in addition to forming the resonant cavity of the laser.Mirrors 124, 126, 128, and 130 are configured for focusing the light toform an image just in front of the frequency doubling crystal 122 on theside closer to mirror 130, and to compensate for thermal lensing in thelasing element. Although mirrors 124, 126, 128, and 130 are illustratedas flat and parallel to the walls of the laser, typically the focusingis achieved by curving and/or angling the mirrors. Alternativelytransmissive optical elements could be used to focus the light andcompensate for the thermal imaging. Mirrors 124, 128 and 130 reflectboth the wavelength of light produced by the lasing element (e.g. 1064nm) and the wavelength of the frequency doubled light (e.g. 532 nm).Mirror 126 only reflects the light originating from the lasing element110 (e.g. 1064 nm) but is transparent to the frequency doubled light(e.g. 532 nm), forming an output window. Higher harmonic outputs mayalso be generated from the 1064 nm line, or other line amplified in thelaser, including third and fourth harmonics, for shorter wavelengths.Other laser systems may be used, including but not limited to Sapphirelasers, diode lasers, and dye lasers, which are adapted to provide theoutput power and wavelengths described herein, including wavelengths inthe ranges from 200 nm to 1000 nm and from 1100 nm to 1800 nm, forexample.

[0056] While a bare fiber may be utilized for certain procedures,optical fiber 106 preferably terminates in a tip 140 having opticalelements, or otherwise adapted, for shaping and/or orienting the beamemitted by optical fiber 106 so as to optimize the tissue ablationprocess.

[0057]FIG. 2 depicts a side-firing probe tip 200, which may be used astip 140 (FIG. 1). The tip 140 is treated to deflect light sideways. Someexamples of methods for deflecting the light sideways are to include alight scattering material in the tip 140 and/or to place a reflectiveelement in the tip 140. The reflective element could be angled at 45°,for example; to deflect the light at 90° with respect to the axis of thefiber 106. Side-firing probe tip 200 includes an optically transparentsleeve 202 having a transparent window 204 (which may be constructed asa cutout in the wall of sleeve 202 through which the beam is emitted ina direction transverse to the optical axis of fiber 106.) An acceptablerange of angles in which to deflect the light beam is between about 40to 120 degrees with respect to the axis of the fiber. The preferredembodiments use an angle of either 70 or 100. The angle of 80° ispreferred from the standpoint of the ease in manufacturing the tip 200and the angle of 90° is preferred from the standpoint of the ease inaiming the side firing light.

[0058] In a typical mode of operation, optical fiber 106 is held withinan endoscope such as a hysteroscope or similar instrument that allowsthe clinician to precisely position the distal end of the optical fiberadjacent to the targeted tissue. The endoscope also has channels forsupplying and removing an irrigant solution to and from the tissue. Inaddition, light and image guides are also included for illuminating andimaging the tissue so that the clinician may direct the laser light andassess the progress and efficacy of the ablation procedure. Physiologicsaline solution, typically containing 0.9% sodium chloride, is used asthe irrigant in gynecological procedures according to the presentinvention.

[0059]FIG. 3 illustrates an exemplary output waveform applied to tissue104 when laser 102 is operated in the macro-pulsed mode. Eachmacro-pulse 302 is defined by a train of Q-switched micro-pulses 304.While a relatively small number of micro-pulses 302 are depicted forpurposes of clarity, an actual macro-pulse may comprise hundreds orthousands of component micro-pulses 304. In the preferred embodimentthere are between 2 and 12,200 micro-pulses per macro-pulse.

[0060] An arc lamp, for example, when used as the pump source 112, iskept at a low power level between pulses that are preferably just enoughto maintain the arc. These low pump powers are below the lasingthreshold of the laser; as a consequence, there is no laser outputbetween macro-pulses.

[0061] As mentioned above, the pulse duration or width D (FIG. 3) of theoutput beam is governed by the modulation of pump source 112, and morespecifically by the period during which the pump source 112 ismaintained in an “on” or high-power condition. In other words, thelonger the pump source 112 is maintained in an on condition, the longerthe pulse width. Typically, laser 102 will be capable of deliveringpulses 302 having pulse durations D in the range of 1 to 20 milliseconds(2 to 490 micro-pulses) or 1 to 50 milliseconds (2 to 1,220micro-pulses) and average output powers preferably exceeding 60 wattsand preferably up to 100 or 200 watts. The ratio of D to the period ofthe macro-pulses defines the duty cycle, which is typically between 10and 50%.

[0062] In accordance with one embodiment of the invention, a lasersystem 100 of the foregoing description is employed to treatgynecological conditions by ablating targeted tissue 104. The clinicianmay utilize an endoscope or similar instrument to guide the distal endand tip 140 of optical fiber 106 into alignment with the targeted tissue104. Laser system 100 is then operated in the macro-pulsed mode so thatlaser 102 generates laser light having the pulsed waveform depicted inFIG. 3 and delivers it through optical fiber 106 to tissue 104.

[0063] Prior art techniques for treatment of gynecological conditions bylaser ablation (such as the technique described by Indman. in“High-Power Nd:YAG Laser Ablation of the Endometrium,” Journal ofReproductive Medicine, Vol. 36, No.7, July 1991)) utilized an Nd:YAGlaser to irradiate the uterine tissue. Although such lasers do producemoderately high average powers, they have a large number of transversemodes and as such, produce highly divergent light when focused intosmall fiberoptics. Further, the 1064 nm wavelength is less efficientlyabsorbed in the target tissue, that the wavelengths desirable accordingto the present invention. These characteristics of prior art 1064 nmsystems lead to less than optimal power densities when the laser lightis directed at tissue. As a consequence, ablation rates are relativelyslow, significantly lengthening procedure times. Further, undesirablethermal damage to deeper tissue layers may occur. In contrast, it hasbeen found that a macro-pulsed beam, such as that generated by laser102, helps to accelerate ablation rates and reducing procedure time.

[0064] The macropulsing can also increase efficiency because thethreshold voltage required for lasing while macropulsing (the operatingthreshold) is lower than the initial threshold voltage for lasing (coldthreshold).

[0065] Macropulsing is also more efficient for producing green lightbecause the conversion of infrared light to frequency doubled lightincreases as the square of the infrared light intensity. The higher peakpowers of the macro-pulsed infrared light leads to higher secondharmonic conversion efficiency. For example, at any given time, theinput power and output power of a frequency-doubled laser using KTP arerelated according to

Po=A(Pi)^(2,)

[0066] Where A is an experimentally determined positive constant. Thisequation relates the peak input power to the peak output power. However,the average input power and output power for a duty cycle of k percentare given by

<Pi>=k(Pi) and

<Po>=k(Po)=kA(Pi)² =A(<Pi>)² /k,

[0067] where the brackets “< >” indicate an average value of theenclosed quantity. Thus, decreasing the duty cycle from 100% to 50%(i.e. reducing k from 1 to 0.5) while simultaneously doubling the peakinput power Pi results in no change to the average input power <Pi> anda doubling of the average output power <Po>. Pulse modulating ormacropulsing using Q-switching, for example, enables reaching higheraverage output powers with less thermal lensing due to the lower inputpower.

[0068] Additionally, it is possible that the frequency doubling crystalhas nonlinearly increasing output power as a function of the inputpower. In other words the second derivative of the output power withrespect to the input power may be positive, in which case the rate ofincrease of the output power increases with increasing input power.Specifically, in such a case the functional dependence of theinstantaneous or peak output power, Po, on the instantaneous or peakinput power, Pi, is such that

d ²(Po)/d(Pi)²>0.

[0069] When this is true, and Po is an increasing function of Pi, thehigher peak input power results in a more efficient laser because ratioof the output to input power increases.

[0070] Pump source modulation of the laser can produce high peak powermacro-pulses and affect the efficiency of the average power output.Macro-pulse in excess of a steady state power can substantially improvethe initiation of the vaporization of tissue. The higher peak power ofthe macro-pulse rapidly may initiate charring which in turn serves as anadditional chromophore for the incident energy and enhances thevaporization rate. A 30% macro-pulse duty cycle is sufficient toincrease the average power output of an arc lamp pumped laser to greaterthan 80 watts. Additionally the pump modulation generates macro-pulsewith pulse powers greater than 240 watts.

[0071] By way of a non-limiting example, tissue 104 may be efficientlyand rapidly ablated when laser 102 is operated at an output power of 80to 100 watts, a pulse duration of 1-50 milliseconds, and a wavelength of532 nm.

[0072] In accordance with a second method embodiment of the invention,laser system 100 may be utilized to ablate other types of tissue 104involved in gynecological conditions. The clinician may utilize anendoscope or similar instrument to guide the distal end and tip 140 ofoptical fiber 106 into alignment with the tissue 104. Laser system 100is then operated in the macro-pulsed mode so that laser light having thepulsed waveform depicted in FIG. 3 is generated by laser 102 anddelivered through optical fiber 106 to tissue 104. To achieve adequateresults, laser system 100 is adjusted to emit a beam having a pulseduration between 0.1 and 500 milliseconds, and an output power of atleast 20 watts. Upon vaporization of the required volume of tissue 104,(which may be assessed via an imaging channel contained in theendoscope), the output beam of laser 102 is turned off.

[0073] In a third method embodiment of the invention, treatment ofgynecological conditions is effected by operating laser 102 in aquasi-CW mode at an output power greater than 60 watts. The increaseddenaturization of the tissue is dramatic with increases in power,suggesting a threshold effect. As depicted in FIG. 4, laser 102generates a continuous train of Q-switched micro-pulses 400 whenoperated in quasi-CW mode. The laser light is then delivered via opticalfiber 106 to targeted tissue 104. Operation in a quasi-CW mode at powersabove 60 watts facilitates formation of char and consequent rapidablation rates, whereas operation in a quasi-CW mode at powers below 60watts forms char more slowly and causes more thermal damage to underlingtissue.

[0074] A fourth embodiment of this invention is to produce a high power,high beam quality laser that can project high power density laser lightonto tissue. To do this the number of transverse optical modes supportedby the resonator needs to be kept as low as possible.

[0075] Small M² and high average powers can be achieved by reducing thedegree of thermal lensing in the laser element. Using laser diodes asthe excitation source is one effective way of greatly reducing both thesize of the lasing element and the thermal gradient responsible forcreating the thermal lens. The reason for this is that while 2-10% ofthe light produced from a flashlamp or arc lamp is converted into usefullaser light 30-60% of the light emitted from laser diodes can beconverted to laser light. Since the energy that is not converted tolaser light is converted into heat, laser diodes deposit significantlyless heat in the lasing element and as a consequence create a lesspowerful thermal lens. In this manner laser diodes can be used to pumpcrystalline laser elements or fiber lasers to produce high beam qualitylasers. Slab and waveguide lasers that can be pumped by laser diodes,arc lamps, or flashlamps are another method of creating low M² lasers.This is because the thermal gradient produced in slab lasers is linearacross the thin dimension of the slab and not radially dependent incontrast to a typical cylindrical lasing element. The linear thermalgradient does not produce a thermal lens resulting in low M² values.

[0076] For example, as a result of the low M² some embodiments of thisinvention are capable producing laser light that upon exiting a flat endof a fiber having a diameter of 600 μm has a divergence of 15.3° orlower; 15° or lower; 10° or lower; or 5° or lower, and the power densitycan be 13,400 watts per cm², or greater.

[0077]FIG. 5 shows a block diagram of a preferred laser system accordingto the present invention. In FIG. 5, a laser resonator is defined by endmirror 10, turning mirrors 12 and 14, and end mirror 16. All of thesemirrors are high reflecting (greater than 99.8%) at the 1064 nm line. Anoptical path 24 is defined by these mirrors. A gain medium 18 comprisinga Nd:YAG rod is mounted along the optical path within a pump housing 29.A laser diode array 28D is also mounted within the housing and suppliespump power to the gain medium in response to current generated in powersupply 30. Representative laser diodes include laser diodes providingoutput in the range of 805 to 820 nm in wavelength with an input powerto the array of pumping diodes in the range of 300 to 500 Watts. Thelaser diodes used for pump energy are operated in a modulatedmacro-pulse mode, or in a continuous mode, as suits a particularimplementation.

[0078] Also in the optical path 24 is a Q-switch 20 between the lamphousing 29 and the turning mirror 12. A non-linear crystal 22 is mountedbetween the turning mirror 14 and the back mirror 16. This non-linearcrystal is preferably a KTP crystal aligned for frequency doubling togenerate a 532 nm beam. Mirrors 16 and 14 are highly reflective at 532nm, while mirror 12 is transmissive and operates as an output couplerfor the 532 nm beam.

[0079] Thus, the laser resonator is designed for resonating at a firstfrequency, i.e., 1064 nm along the Z-shaped optical path 24. A secondfrequency derived from the 1064 nm beam is generated in the KTP crystal22. This beam travels along the path 26 a and is extracted from theresonator to supply an output beam along path 26 b.

[0080] The output beam along path 26 b passes through a controllableattenuator 36, a beam splitter 38, which supplies a portion of theoutput beam to a surgical detector 40, and a component group 42 asdescribed in more detail below. The attenuator, detector, and componentgroup are all coupled to a data processing system 34, across lines 34 j,34 k, and 34 p.

[0081] The Q-switch 20 is controlled by Q-switch driver 21, which is, inturn, coupled to data processor 34 across line 34 i. In the preferredsystem, the Q-switch is an acoustic-optic Q-switch.

[0082] Similarly, the power supply 30 generates an electrical powersignal for controlling the diode array 28D. This power signal iscontrolled by the data processor 34 across line 34 h and by drivecircuitry 32 across line 32 a. Drive circuitry 32 a is controlled by thedata processor across lines 34 a through 34 g. A sensor 57 is coupledwith the data processor to sense an environmental condition, such astemperature or humidity, that affects operation of the laser system. Amodem 56 is connected to the data processor 34, providing an interfacefor remote access to memory in the data processor. Finally, a controlpanel 35, by which a user can supply input signals and parameters, isprovided. This control panel 35 is connected to the data processor 34across line 34 n.

[0083] In alternative systems, the non-linear crystal may be mountedoutside the resonant cavity of the resonator. Also, it may be used forextracting outputs other than the second harmonic, such assum-of-frequency derivation or the like.

[0084] The wavelength used according to the present invention forgynecological conditions treatment should be strongly absorbed in thetissue to help initiate and maintain tissue vaporization withoutcreating deep tissue heating. The wavelength also must be minimallyabsorbed by the irrigant used during the procedure, typicallyphysiologic saline solution. The 532 nm light produced by the system ofFIG. 5, is both strongly absorbed in oxyhemoglobin and weakly absorbedin physiologic saline solution. Oxyhemoglobin is readily present inuterine tissue and serves as an efficient chromophore for 532 nm light.The differential in absorption coefficients between oxyhemoglobin andwater at 532 nm is approximately 5 orders of magnitude (10⁵). In otherembodiments, wavelengths in the range from 200 nm-650 nm are used, whichhave strong oxyhemoglobin absorption and relatively weak waterabsorption (>10²X). In yet other embodiments, wavelengths in the rangefrom 200 nm to 650 nm range are used, which have strong oxyhemoglobinabsorption and relatively weak water absorption (>10X).

[0085] Of course, as shown in FIG. 6, in which like components have thesame reference numerals as in FIG. 5, alternative pump power sources,such as arc lamps 28, and flash lamps, other lasers for longitudinalpumping, and others, can be used as suits the needs of a particular gainmedium and application of the laser system.

[0086] The laser systems shown in FIGS. 5 and 6 can be modified byremoving both the Q-switch and the external surgical attenuator. TheQ-switch and surgical attenuator are removed because the modulated pumppower provides a great deal of flexibility in controlling the outputpower of the laser not attainable using a Q-switch. The data processingsystem can be programmed to maintain a constant thermal load in thelaser system while varying the peak pump power widely. Thus, the peakcurrent and duty cycle of the pump power source can be adjusted in sucha way to keep the average pump power constant, but the second harmonicpower during the ready and work modes adjusted by selecting the peakcurrent and duty cycle. Although it may be necessary to use attenuatorsin the beamline during the ready mode in order to extract an aim beam,such attenuators may well be eliminated for the work mode. The averagepower does not have to be constant, rather it can be maintained atlevels which keep thermal focusing of the gain medium within the rangeof stability of the resonator.

[0087] A representative laser system adapted for delivery of energy asdescribed above, comprises an 80 watt average power, 532 nm outputwavelength, solid state, intra-cavity frequency doubled Nd:YAG laser. Toobtain optimal efficiency, an arc lamp pump source is modulated at aperiod of 4.5 ms with a 16 ms duty cycle, generating 285 watts peakmacro-pulse power. An intra-cavity acousto-optic AO Q-switch is used tofurther modulate the energy at a period of 40 kHz with a 450 usmicro-pulse. The laser energy is coupled to a side firing fiber opticdelivery device for delivery to uterine tissue.

[0088] The laser system uses a combination touch screen and control knobuser interface to assist the operator in setting up the surgicalparameters, including power levels and pulse sequence specifications.The average power setting is prominently displayed on the screen.Parameter adjustments are made by first activating (touching) thedesired parameter box on the screen and then turning the knob. The lasersystem uses a secure card key interface to enable the laser. The systemis transportable. The system offers convenient storage and a fiberdelivery device pole.

[0089] An example of an endoscope, in particular a hysteroscope, for usewith the present invention is shown in FIG. 7. The hysteroscope has adistal end 200 and a proximal end 201. Laser radiation 205 is directedfrom and end firing fiber through an opening 206, by a fiber opticcomponent. Water, Ringer Lactate or saline solution is delivered andremoved from the treatment area via lumens in the probe. A viewing opticis also placed in the opening 206, by which the surgeon is able to viewthe treatment area during the procedure. On the proximal end 201 of theendoscope, an irrigation port 203 for flow of the irrigant is provided.Also, a fiber port 207 is used for insertion and removal of the fiberoptic delivering laser radiation to the treatment area. A light sourceconnector 209 is used for supplying light to the treatment area forvisualization. An viewing port 211, which can be coupled to a videocamera, or looked into directly, is also included on the representativehysteroscope. The endoscope includes a flexible tip in one embodiment,and controls (not shown) in the near proximal end 201, by which thesurgeon deflects and guides the positioning of the tip at distal end200. Representative systems for providing flexible tip endoscopes aredescribed in U.S. Pat. No. 4,802,461, and are widely used for surgicalprocedures.

[0090] The vaporization of uterine tissue using oxyhemoglobin as theprimary chromophore is related to the incident power density, orirradiance, which can be expressed in Watts/cm². The overall rate ofuterine tissue vaporization is a function of the spot size, absorptiondepth, and the power density. A large spot with high power density, andrapid absorption is ideal to rapidly vaporize tissue. A high power lightsource is required to achieve a large spot, high power density treatmentbeam. Peak laser power, average laser power, beam quality, deliverydevice design and delivery device placement all affect the efficiency ofvaporization. A treatment beam 28.5 Kw/cm² average irradiance with a85.5 Kw/cm² peak irradiance macro-pulse, with a spot size between about0.2 and 0.5 mm², rapidly vaporizes tissue.

[0091]FIGS. 8 and 9 illustrate the different optical penetration depthsof the 532 nm wavelength and 1064 nm wavelength used in prior artprocedures. See, S. L. Jacques. Laser-tissue interaction. Photochemical,photothermal, and photomechanical. Surg. Clin N. Am. 1992;72(3):531-558.The optical penetration depth of the 1064 wavelength beam from Nd:YAGlaser beam is about 10 mm, which is 13 times larger than the penetrationdepth of the second harmonic 532 wavelength laser beam, which is about0.8 mm. As a result, the 1064 laser power is spread out over a muchlarger tissue volume than the power of the KTP laser. In case of the1064 laser as shown in FIG. 9, the temperature at the tissue surfacebarely reaches 100° C. Therefore, only a small portion of tissue getsvaporized. But a huge volume of tissue gets coagulated (see spacebetween 100° C. and 60° C. isotherm).

[0092] The 532 laser beam, in contrast, is substantially completelyabsorbed within less than about 1 mm of the surface of uterine tissue.The laser power is confined to a very small tissue volume. The highvolumetric power density results in a fast heating of the tissue andefficient tissue vaporization. Volumetric power density delivered totissue is a function of the absorbtion depth, irradiance in Watts/cm²and spot size on the surface of the tissue. The coagulation zone is verythin because of the small optical penetration depth of the 532wavelength, and because substantially all of the radiation is convertedto vaporization rather than residual heat.

[0093] Other wavelengths which are substantially completely absorbedwithin less than about 1 mm of the surface of the uterine tissue includewavelengths between about 200 and 1000 nm, including wavelengths lessthan about 700 nm, for example between about 200 nm and 650 nm.

[0094]FIGS. 10 and 11 illustrate a profile of a beam delivered to tissueusing one representative side firing optical fiber, to show spot size asa function of distance from the side of the optical fiber. FIG. 10 is anend view, showing a fiber 600, cladding 601 on the fiber, an air space602, and a tip 603 through which the beam is directed by a reflectingface on the fiber. The cross-section of the beam is represented by thecrossing lines 604 and 605. As shown, the beam has a width in thisdimension of about 0.35 mm at 1 mm from the side of the tip 603. Atabout 2 mm from the side of the tip 603, the width is about 1 mm. Atabout 3 mm distance from the side of the tip 603, the beam width isabout 2.2 mm.

[0095]FIG. 11 is a side view, with like components given the samereference numbers. The beam width in this dimension is represented bylines 606 and 607. As shown, the beam has a width in this dimension ofabout 0.7 mm at 1 mm from the side of the tip 603. At about 2 mm fromthe side of the tip 603, the width is about 1 mm. At about 3 mm distancefrom the side of the tip 603, the beam width is about 1.5 mm.

[0096] Thus, the spot size at 1 mm from the side of the tip is definedbasically by an ellipse having a major axis of 0.7 mm, and a minor axisof 0.35 mm. The area of the spot at 1 mm is around 0.2 mm². At 2 mm fromthe side, the area of the spot is about 0.8 mm².

[0097] For rapid procedures, according to the present invention, thespot size should be large enough that the operator can remove tissue ata reasonable rate, and see the results of a single pass of the spot overa region of tissue. If the spot size is too small, the rate of theoperation is too slow. Also, if the spot size is too big, then theprocedure is difficult to control precisely. A preferred spot size isless than about 1 mm², and more particularly between about 0.8 mm² andabout 0.05 mm². Other apparatus may be used for delivery of the beamwith the desired spot size, including embodiments without divergingbeams, and embodiments with converging beams.

[0098] The irradiance of the beam at 1 mm from the side of the tip foran 80W average power laser as described above is about 30 kiloWatts/cm².According to the present invention, it is desirable to provide awavelength between about 650 and 200 nm, with a spot size on the surfaceof the tissue less than about 0.8 mm², and preferably greater than about0.05 mm², with an irradiance greater than about 10 kiloWatts/cm², andmore preferably greater than 20 kiloWatts/cm², and even more preferably30 kiloWatts/cm² or higher.

[0099]FIG. 12 shows, heuristically, how vaporization rate andcoagulation rate depend on the volumetric power density. Thevaporization rate (in mm/s) is defined as tissue depth that is vaporizedper time interval. The coagulation rate (in mm/s) is defined as thedepth of residual coagulated tissue that remains after a certain time ofvaporization.

[0100] Below a certain volumetric power density, referred to as a“vaporization threshold” in FIG. 12, no tissue gets vaporized. All laserenergy stays inside the tissue. Tissue coagulation occurs where thetissue temperature rises above approximately 60° C. As the volumetricpower density is increased a bigger and bigger tissue volume getscoagulated.

[0101] At the vaporization threshold, vaporization starts. Above thevaporization threshold the vaporization rate can be considered toincrease linearly with the volumetric power density for the purpose ofunderstanding the present invention, and as described by a steady statemodel for continuous wave laser tissue ablation, known by those familiarwith the art of laser-tissue interaction.

[0102] As more and more laser energy is consumed by vaporization of thetissue, the amount of laser energy leading to residual tissuecoagulation gets smaller, i.e. the amount of residual coagulation drops.Thus, extent of the zone of thermal damage characterized by tissuecoagulation left after the procedure gets smaller with increasingvolumetric power density, while the rate of vaporization increases.Substantial and surprising improvement in results is achieved.

[0103] Publications about visual laser ablation of the prostate (VLAP)that is performed with an Nd:YAG laser at 1064 nm have shown that thistype of laser is not able to vaporize a significant amount of tissue.Histology studies have shown that the 1064 nm laser induces deepcoagulation in the tissue that results in edema and delayed tissuesloughing. This effect was described by Kuntzman, et al., High-powerpotassium titanyl phosphate laser vaporization prostatectomy. Mayo ClinProc 1998:73:798-801. Thus, in the heuristic diagram of FIG. 12, theVLAP procedure is believed to lie around point 650, barely above thevaporization threshold. Also, prior art technologies using 532 nm withspot sizes on the order of 1 mm² with average output power of 60 Watts,are believed to lie, heuristically, around point 651 in the FIG. 12.Kuntzman et al present results for the coagulation depth of a 60 Wcontinuous wave 532 nm laser, with suggested operation at a distance of2 mm from the side of the tip, yielding less than 5 kiloWatts/cm²irradiance.

[0104] As the laser power is further increased to 80 W, and the sidefiring probe is placed less than 1 mm from the tissue for a small spotsize, the ablation rate further increases and the coagulation ratefurther drops, so that the procedure lies heuristically at point 652 inFIG. 12.

[0105] A 80 Watt KTP laser can be used to easily reach irradiance levelsthat vaporize substantially more tissue than is left as residualcoagulation after the procedure. More precisely, the vaporization rateis substantially higher than the coagulation rate as given by thedefinition above, using high irradiance levels that are easily achievedwith higher power lasers. Because of higher vascularization in theuterus, the optical penetration depth is lower than in prostatic tissue,and therefore the volumetric power density at the vaporization thresholdcan be easily reached with lower average power lasers, including forexample a 40 W average output power laser.

[0106]FIG. 13 illustrates a uterus, generally 500, having myomastreatable according to the present invention, including intracaviteryprotruding myomas 501, 502, intracavitery pedunculated myoma 503, andintramural, submucosal myoma 540. Myoma 502 is located in the rightcornu. Hysteroscope 505 is positioned through the cervix 506 with aflexible tip 507 adjacent myoma 502, and delivering laser radiation asdescribed above.

[0107]FIG. 14 illustrates use of a side firing probe 509 for treatmentof a myoma 510 located in one of the uterine cornua. FIG. 15 illustratesuse of an end firing probe 511, for treatment of a myoma 512 located inone of the uterine cornua.

[0108] While the invention has been particularly shown and describedwith reference to preferred embodiments thereof, it will be understoodby those skilled in the art, that various changes in form and detailsmay be made therein without departing from the spirit and scope of theinvention, as defined by the appended claims.

What is claimed is:
 1. A method for photoselective vaporization oftissue for treatment of gynecological conditions, comprising: deliveringlaser radiation to a treatment area on a surface of tissue of a femalereproductive organ, the laser radiation being absorbed substantiallycompletely by the tissue within about 1 mm of the surface, and havingaverage irradiance in the treatment area greater than 10 kiloWatts/cm²in a spot size at least about 0.05 mm².
 2. The method of claim 1,wherein the spot size is between about 0.1 and 0.8 mm² in the treatmentarea.
 3. The method of claim 1, wherein the irradiance is at least 30kiloWatts/cm² in the treatment area.
 4. The method of claim 1, whereinthe laser radiation has a wavelength in a range from about 200 to about700 mn.
 5. The method of claim 1, wherein the delivered laser radiationhas a wavelength in a range of about 200 nm to about 700 mn, and has anaverage irradiance in the treatment area greater than 20 kiloWatts/cm².6. The method of claim 1, wherein the delivered laser radiation has awavelength in a range of about 200 nm to about 700 nm, and has anaverage irradiance in the treatment area greater than 30 kiloWatts/cm².7. The method of claim 1, wherein said tissue comprises uterine tissue.8. The method of claim 1, wherein said tissue comprises uterine tissuelocated in a cornua of the uterus.
 9. The method of claim 1, whereinsaid delivering comprises using a hysteroscope, with an optical fiberadapted to direct laser radiation from the fiber to the treatment area.10. The method of claim 1, wherein said delivering comprises using ahysteroscope, with an optical fiber having a side firing optical elementdirecting laser radiation from the fiber to the treatment area, andplacing said side firing optical element within about 1 mm, or less, ofthe treatment area.
 11. The method of claim 1, wherein said deliveringcomprises using a hysteroscope, with an end firing optical fiber adaptedfor directing laser radiation from the fiber to the treatment area, andplacing said end firing optical fiber within about 1 mm, or less, of thetreatment area.
 12. The method of claim 1, including generating saidlaser radiation using a solid state laser with greater than 40 Wattsaverage output power.
 13. The method of claim 1, including generatingsaid laser radiation using a solid state laser with greater than 60Watts average output power.
 14. The method of claim 1, includinggenerating laser radiation using a macro-pulsed solid state laser havingoutput power greater than about 200 Watts during a macro-pulse.
 15. Themethod of claim 1, wherein said delivering comprises delivering amacro-pulse consisting of a sequence of micro-pulses of laser radiation,and said irradiance is greater than 50 kiloWatts/cm² during themacro-pulse.
 16. The method of claim 1, including generating said laserradiation using Neodymium doped solid state laser medium, and optics toproduce an output at a second or higher harmonic frequency with greaterthan 40 Watts average output power.
 17. The method of claim 1, whereinthe laser radiation has a beam quality (M²) that is less than or equalto
 100. 18. The method of claim 1, wherein said tissue comprises uterinetissue, and said treatment is for a gynecological condition selectedfrom leiomyoma uteri, rhabdomyoma, endometriosis, endometrialhyperplasia, endometrial cysts, endometrial polyps, menorrhagia, uterinesepta, intrauterine adhesions, or cervical intraepithelial neoplasia.19. A method for photoselective vaporization of tissue of a femalereproductive organ, comprising: delivering laser radiation and a flow ofa transparent liquid irrigant to a treatment area on a surface of targettissue of a female reproductive organ, the laser radiation causingvaporization of a volume of tissue greater than a volume of residualcoagulation of tissue, and having irradiance in the treatment areagreater than 10 kiloWatts/cm² in a spot size at least 0.05 mm².
 20. Themethod of claim 19, wherein the spot size is less than about 0.8 mm² inthe treatment area.
 21. The method of claim 19, wherein the irradianceis at least 30 kiloWatts/cm² in the treatment area.
 22. The method ofclaim 19, wherein the laser radiation has a wavelength in a range fromabout 200 to about 700 nm.
 23. The method of claim 19, wherein thedelivered laser radiation has a wavelength in a range of about 200 nm toabout 700 nm, and has an average irradiance in the treatment areagreater than 20 kiloWatts/cm².
 24. The method of claim 19, wherein thedelivered laser radiation has a wavelength in a range of about 200 nm toabout 700 nm, and has an average irradiance in the treatment areagreater than 30 kiloWatts/cm².
 25. The method of claim 19, wherein theirrigant comprises physiologic saline.
 26. The method of claim 19,wherein the irrigant comprises Ringer Lactate.
 27. The method of claim19, wherein said delivering comprises using a hysteroscope with aflexible tip, with an optical fiber adapted to direct laser radiationfrom the fiber to the treatment area.
 28. The method of claim 19,wherein said delivering comprises using a hysteroscope, with an opticalfiber adapted to direct laser radiation from the fiber to the treatmentarea.
 29. The method of claim 19, wherein said delivering comprisesusing a hysteroscope, with an optical fiber having a side firing opticalelement directing laser radiation from the fiber to the treatment area,and placing said side firing optical element within about 1 mm, or less,of the treatment area.
 30. The method of claim 19 wherein saiddelivering comprises using a hysteroscope, with an end firing opticalfiber directing laser radiation from the fiber to the treatment area,and placing said end firing optical fiber within about 1 mm, or less, ofthe treatment area.
 31. The method of claim 19, including generatingsaid laser radiation using a solid state laser with greater than 40Watts average output power.
 32. The method of claim 19, includinggenerating said laser radiation using a solid state laser with greaterthan 60 Watts average output power.
 33. The method of claim 19,including generating laser radiation using a macro-pulsed solid statelaser having output power greater than about 200 Watts during amacro-pulse.
 34. The method of claim 19, wherein said deliveringcomprises delivering a macro-pulse consisting of a sequence ofmicro-pulses of laser radiation, and said irradiance is greater than 50kiloWatts/cm² during a macro-pulse.
 35. The method of claim 19,including generating said laser radiation using Neodymium doped solidstate laser medium, and optics to produce an output at a second orhigher harmonic frequency with greater than 40 Watts average outputpower.
 36. The method of claim 19, wherein the laser radiation has abeam quality (M²) that is less than or equal to
 100. 37. The method ofclaim 19, wherein said target tissue comprises uterine tissue, and saidtreatment is for a gynecological condition selected from leiomyomauteri, rhabdomyoma, endometriosis, endometrial hyperplasia, endometrialcysts, endometrial polyps, menorrhagia, uterine septa, intrauterineadhesions, or cervical intraepithelial neoplasia.
 38. A method forphotoselective vaporization of tissue for treatment of a gynecologicalcondition, comprising: delivering laser radiation to a treatment area ontissue of a female reproductive organ, the laser radiation having awavelength and having irradiance in the treatment area sufficient tocause vaporization of a substantially greater volume of said tissue thana volume of residual coagulated tissue caused by the laser radiation.39. The method of claim 38, wherein the delivered laser radiation has anaverage irradiance in the treatment area greater than 10 kiloWatts/cm²in a spot size at least 0.05 mm².
 40. The method of claim 38, includingdelivering said laser radiation using an optical fiber, and wherein thedelivered laser radiation has a wavelength in a range of about 200 nm toabout 650 nm, and has an average irradiance in the treatment areagreater than 10 kiloWatts/cm² and the optical fiber is adapted to causea spot size of at least about 0.05 mm² in the treatment area.
 41. Themethod of claim 38, wherein the delivered laser radiation has awavelength in a range of about 200 nm to about 650 nm, and has anaverage irradiance in the treatment area greater than 20 kiloWatts/cm²and the optical fiber is adapted to cause a spot size of at least about0.05 mm² in the treatment area.
 42. The method of claim 38, wherein thedelivered laser radiation has a wavelength in a range of about 200 nm toabout 650 nm, and has an average irradiance in the treatment areagreater than 30 kiloWatts/cm² and the optical fiber is adapted to causea spot size of at least about 0.05 mm² in the treatment area.
 43. Themethod of claim 38, wherein the spot size is less than about 0.8 Mm² inthe treatment area.
 44. The method of claim 38, wherein the averageirradiance is at least 30 kiloWatts/cm² in the treatment area.
 45. Themethod of claim 38, wherein the laser radiation has a wavelength in arange from about 200 to about 700 nm.
 46. The method of claim 38,including delivering a flow of irrigant to the treatment area.
 47. Themethod of claim 38, wherein the tissue comprises uterine tissue.
 48. Themethod of claim 38, wherein said delivering comprises using ahysteroscope, with an optical fiber adapted to direct laser radiationfrom the fiber to the treatment area.
 49. The method of claim 38,wherein said delivering comprises using a hysteroscope, with an opticalfiber having a side firing optical element directing laser radiationfrom the fiber to the treatment area, and placing said side firingoptical element within about 1 mm, or less, of the treatment area. 50.The method of claim 38, wherein said delivering comprises using ahysteroscope, with an end firing optical fiber directing laser radiationfrom the fiber to the treatment area, and placing said end firingoptical fiber within about 1 mm, or less, of the treatment area.
 51. Themethod of claim 38, including generating said laser radiation using asolid state laser with greater than 40 Watts average output power. 52.The method of claim 38, including generating said laser radiation usinga solid state laser with greater than 60 Watts average output power. 53.The method of claim 38, including generating laser radiation using amacro-pulsed solid state laser having output power greater than about200 Watts during a macro-pulse.
 54. The method of claim 38, wherein saiddelivering comprises delivering a macro-pulse consisting of a sequenceof micro-pulses of laser radiation, and said irradiance is greater than50 kiloWatts/cm² during the macro-pulse.
 55. The method of claim 38,including generating said laser radiation using Neodymium doped solidstate laser medium, and optics to produce an output at a second orhigher harmonic frequency with greater than 40 Watts average outputpower.
 56. The method of claim 38, including generating said laserradiation using a diode-pumped, Neodymium doped solid state lasermedium, and optics to produce an output at a second or higher harmonicfrequency with greater than 40 Watts average output power.
 57. Themethod of claim 38, wherein the laser radiation has a beam quality (M²)that is less than or equal to
 100. 58. The method of claim 38, whereinsaid tissue comprises uterine tissue, and said treatment is for agynecological condition selected from leiomyoma uteri, rhabdomyoma,endometriosis, endometrial hyperplasia, endometrial cysts, endometrialpolyps, menorrhagia, uterine septa, intrauterine adhesions, or cervicalintraepithelial neoplasia.
 59. A method for photoselective vaporizationof gynecological tissue, comprising: generating laser radiation using aNeodymium doped solid state laser medium, and optics producing a secondor higher harmonic output with greater than 40 Watts average outputpower; coupling said output to an optical fiber in an endoscope having aflexible tip, the optical fiber adapted to direct laser radiation fromthe fiber to a treatment area on a surface of the tissue; delivering aflow of irrigant to the treatment area; and delivering laser radiationto a treatment area on the tissue via the optical fiber, the laserradiation having a wavelength and having irradiance in the treatmentarea sufficient to cause vaporization of a substantially greater volumeof tissue than a volume of residual coagulated tissue caused by thelaser radiation.
 60. The method of claim 59, wherein said average outputpower is greater than 60 watts.
 61. The method of claim 59, wherein thedelivered laser radiation has an average irradiance in the treatmentarea greater than 10 kiloWatts/cm² and the optical fiber is adapted tocause a spot size of at least about 0.05 mm² in the treatment area. 62.The method of claim 59, wherein the delivered laser radiation has anaverage irradiance in the treatment area greater than 20 kiloWatts/cm²and the optical fiber is adapted to cause a spot size of at least about0.05 mm² in the treatment area.
 63. The method of claim 59, wherein thedelivered laser radiation has an average irradiance in the treatmentarea greater than 30 kiloWatts/cm² and the optical fiber is adapted tocause a spot size of at least about 0.05 mm² in the treatment area. 64.The method of claim 59, wherein the delivered laser radiation has anaverage irradiance in the treatment area greater than 10 kiloWatts/cm²,and the optical fiber is adapted to cause a spot size is less than about0.8 mm² in the treatment area.
 65. The method of claim 59, wherein theaverage irradiance is at least 30 kiloWatts/cm² in the treatment area.66. The method of claim 59, wherein the optical fiber includes a sidefiring tip, and including placing said side firing tip within about 1mm, or less, of the treatment area.
 67. The method of claim 59, whereinthe optical fiber includes an end firing tip, and including placing saidend firing tip within about 1 mm, or less, of the treatment area. 68.The method of claim 59, including Q-switching said laser medium toproduce micro-pulses during application of input power to the lasermedium, and applying input power to the laser medium in a sequence ofpulses to generate macro-pulses of output radiation, and wherein saidoutput power is greater than about 200 Watts during said macro-pulses.69. The method of claim 59, including Q-switching said laser medium toproduce micro-pulses during application of input power to the lasermedium, and applying input power to the laser medium in a sequence ofpulses to generate macro-pulses of output radiation, and said irradianceis greater than 50 kiloWatts/cm² during the macro-pulse.
 70. The methodof claim 59, wherein the laser radiation has a beam quality (M²) that isless than or equal to
 100. 71. The method of claim 59, wherein saidtissue comprises uterine tissue, and said treatment is for agynecological condition selected from leiomyoma uteri, rhabdomyoma,endometriosis, endometrial hyperplasia, endometrial cysts, endometrialpolyps, menorrhagia, uterine septa, intrauterine adhesions, or cervicalintraepithelial neoplasia.
 72. An apparatus for photoselectivevaporization of tissue of a female reproductive organ, comprising: alaser producing laser radiation; a hysteroscope, including an opticalfiber coupled to the laser, adapted to direct laser radiation from thefiber, and a flow of irrigant to a treatment area on a surface of thetissue; and optical fiber being adapted to deliver the laser radiationat a wavelength and irradiance in the treatment area sufficient to causevaporization of a substantially greater volume of tissue than a volumeof residual coagulated tissue caused by the laser radiation.
 73. Theapparatus of claim 72, wherein the laser comprises a Neodymium dopedsolid state laser medium, and optics producing a second or higherharmonic output with greater than 40 Watts average output power.
 74. Theapparatus of claim 72, wherein the laser comprises a Neodymium dopedsolid state laser medium, and optics producing a second or higherharmonic output with greater than 60 Watts average output power.
 75. Theapparatus of claim 72, wherein the laser and optical fiber are adaptedto deliver laser radiation having a wavelength in a range of about 200nm to about 700 nm, and has an average irradiance in the treatment areagreater than 10 kiloWatts/cm² and the optical fiber is adapted to causea spot size of at least about 0.05 mm² in the treatment area.
 76. Theapparatus of claim 72, wherein the laser and optical fiber are adaptedto deliver laser radiation having a wavelength in a range of about 200nm to about 700 nm, and has an average irradiance in the treatment areagreater than 20 kiloWatts/cm² and the optical fiber is adapted to causea spot size of at least about 0.05 mm² in the treatment area.
 77. Theapparatus of claim 72, wherein the laser and optical fiber are adaptedto deliver laser radiation having a wavelength in a range of about 200nm to about 700 nm, and has an average irradiance in the treatment areagreater than 30 kiloWatts/cm² and the optical fiber is adapted to causea spot size of at least about 0.05 mm² in the treatment area.
 78. Theapparatus of claim 72, wherein the laser and optical fiber are adaptedto deliver laser radiation having a wavelength in a range of about 200nm to about 700 nm, and has an average irradiance in the treatment areagreater than 10 kiloWatts/cm², and the optical fiber is adapted to causea spot size is less than about 0.8 mm² in the treatment area.
 79. Theapparatus of claim 72, wherein the laser and optical fiber are adaptedto deliver average irradiance of at least 30 kiloWatts/cm² in thetreatment area.
 80. The apparatus of claim 72, wherein the optical fiberincludes a side firing tip, and is further adapted for placement of saidside firing tip within about 1 mm, or less, of the treatment area. 81.The apparatus of claim 72, wherein the optical fiber includes an endfiring tip, and is further adapted for placement of said end firing tipwithin about 1 mm, or less, of the treatment area.
 82. The apparatus ofclaim 72, wherein the laser includes a Q-switch to produce micro-pulsesduring application of input power to the laser medium, and a powersource applying input power to the laser medium in a sequence of pulsesto generate macro-pulses of output radiation, and wherein said outputpower is greater than about 200 Watts during said macro-pulses.
 83. Theapparatus of claim 72, wherein the laser includes a Q-switch to producemicro-pulses during application of input power to the laser medium, anda power source applying input power to the laser medium a sequence ofpulses to generate macro-pulses of output radiation, and said irradianceis greater than 50 kiloWatts/cm² during the macro-pulse.
 84. The methodof claim 72, wherein the laser radiation has a beam quality (M²) that isless than or equal to
 100. 85. The method of claim 72, wherein saidtissue comprises uterine tissue, and said treatment is for agynecological condition selected from leiomyoma uteri, rhabdomyoma,endometriosis, endometrial hyperplasia, endometrial cysts, endometrialpolyps, menorrhagia, uterine septa, intrauterine adhesions, or cervicalintraepithelial neoplasia.
 86. An apparatus for photoselectivevaporization of tissue of a female reproductive organ, comprising: alaser producing laser radiation having a wavelength in a range fromabout 200 nm to about 700 nm; an endoscope, including an optical fibercoupled to the laser, adapted to direct laser radiation from the fiber,and a flow of irrigant to a treatment area on a surface of the tissue;the laser and optical fiber being adapted to deliver the laser radiationwith an average irradiance in the treatment area greater than 10kiloWatts/cm² and the optical fiber is adapted to cause a spot size ofat least about 0.05 mm² in the treatment area.
 87. The apparatus ofclaim 86, wherein the laser comprises a Neodymium doped solid statelaser medium, and optics producing a second or higher harmonic outputwith greater than 40 Watts average output power.
 88. The apparatus ofclaim 86, wherein the laser comprises a Neodymium doped solid statelaser medium, and optics producing a second or higher harmonic outputwith greater than 60 Watts average output power.
 89. The apparatus ofclaim 86, wherein the laser and optical fiber are adapted to deliverlaser radiation having an average irradiance in the treatment areagreater than 20 kiloWatts/cm².
 90. The apparatus of claim 86, whereinthe laser and optical fiber are adapted to deliver laser radiationhaving an average irradiance in the treatment area greater than 30kiloWatts/cm².
 91. The apparatus of claim 86, wherein the laser andoptical fiber are adapted to deliver laser radiation having a spot sizeis less than about 0.8 mm² in the treatment area.
 92. The apparatus ofclaim 86, wherein the optical fiber includes a side firing tip, and isfurther adapted for placement of said side firing tip within about 1 mm,or less, of the treatment area.
 93. The apparatus of claim 86, whereinthe optical fiber includes an end firing tip, and is further adapted forplacement of said end firing tip within about 1 mm, or less, of thetreatment area.
 94. The apparatus of claim 86, wherein the laserincludes a Q-switch to produce micro-pulses during application of inputpower to the laser medium, and a power source applying input power tothe laser medium in a sequence of pulses to generate macro-pulses ofoutput radiation, and wherein said output power is greater than about200 Watts during said macro-pulses.
 95. The apparatus of claim 86,wherein the laser includes a Q-switch to produce micro-pulses duringapplication of input power to the laser medium, and a power sourceapplying input power to the laser medium a sequence of pulses togenerate macro-pulses of output radiation, and said irradiance isgreater than 50 kiloWatts/cm² during the macro-pulse.
 96. The apparatusof claim 86, wherein the laser radiation has a beam quality (M²) that isless than or equal to
 100. 97. The apparatus of claim 86, wherein saidtissue comprises uterine tissue, and said treatment is for agynecological condition selected from leiomyoma uteri, rhabdomyoma,endometriosis, endometrial hyperplasia, endometrial cysts, endometrialpolyps, menorrhagia, uterine septa, intrauterine adhesions, or cervicalintraepithelial neoplasia.
 98. A method for treating gynecologicalconditions, comprising: providing a solid-state laser emitting lightwith a wavelength of 200 to 1000 nm having a laser element positioned toreceive pump radiation from a pump radiation source; modulating the pumpradiation source to cause the laser element to emit laser light havingpulse duration between 0.1 and 500 milliseconds and pulse frequenciesbetween 1 and 500 Hz; and delivering the laser light to targeted tissueof a female reproductive organ.
 99. The method of claim 98, wherein thelight is of a wavelength that is better absorbed by the targeted tissuethan by a substance in an intermediate position between the tissue and adevice used to deliver the laser light to the tissue.
 100. The method ofclaim 98, wherein the output power density of the light delivered to thetargeted tissue is high enough to vaporize the tissue.
 101. The methodof claim 98, wherein the laser light has a repetition rate of between 1Hertz and 500 Hertz.
 102. The method of claim 98, wherein saiddelivering includes using an optical fiber which terminates in anend-firing probe emitting the laser light from an end of the opticalfiber.
 103. The method of claim 98, wherein said delivering includesusing an optical fiber that terminates in a side-firing probe emittingthe laser light in a direction transverse to the longitudinal axis ofthe optical fiber.
 104. The method of claim 98, wherein the laserfurther comprises a frequency doubling element.
 105. The method of claim98, wherein the step of delivering the laser light further comprisestransmitting the laser light through an optical fiber.
 106. The methodof claim 98, wherein the laser element is fabricated from neodymiumdoped YAG (Nd:YAG).
 107. The method of claim 98, further comprising thestep of Q-switching the laser to produce a train of micropulses, eachmicropulse train collectively form a pulse.
 108. The method of claim 98,wherein the pump radiation source is a laser diode.
 109. The method ofclaim 98, wherein the pump radiation source is an arc lamp.
 110. Themethod of claim 98, wherein the pump radiation source is a flash lamp.111. The method of claim 98, wherein the laser radiation has a beamquality (M²) that is less than or equal to
 100. 112. The method of claim98, wherein said tissue comprises uterine tissue, and said treatment isfor a gynecological condition selected from leiomyoma uteri,rhabdomyoma, endometriosis, endometrial hyperplasia, endometrial cysts,endometrial polyps, menorrhagia, uterine septa, intrauterine adhesions,or cervical intraepithelial neoplasia.
 113. A method for treatinggynecological conditions comprising: providing a solid-state laseremitting light of a wavelength of 200 to 700 nm having a laser elementpositioned to receive pump radiation from a pump radiation source, andthe laser has a beam quality (M²) that is less than or equal to 100, anddelivering the laser light to tissue of a female reproductive organ.114. The method of claim 113, wherein the light is of a wavelength thatis better absorbed by said tissue than by a substance in an intermediateposition between the tissue and a device used to deliver the laser lightto the tissue.
 115. The method of claim 113, wherein the output powerdensity of the light delivered to the targeted tissue is high enough tovaporize the tissue.
 116. The method of claim 113, wherein saiddelivering the laser light comprises transmitting the laser lightthrough an optical fiber.
 117. The method of claim 113, wherein thelaser light has a repetition rate of between 1 Hertz and 500 Hertz. 118.The method of claim 113, wherein the optical fiber terminates in anend-firing probe emitting the laser light from an end of the opticalfiber.
 119. The method of claim 113, wherein the optical fiberterminates in a side-firing probe emitting the laser light in adirection transverse to the longitudinal axis of the optical fiber. 120.The method of claim 113, wherein the laser further comprises a frequencydoubling element.
 121. The method of claim 113, further comprisingQ-switching the laser to produce a train of micropulses, each micropulsetrain collectively comprising a pulse.
 122. The method of claim 113,wherein the pump radiation source is a laser diode.
 123. The method ofclaim 113, wherein the pump radiation source is an arc lamp.
 124. Themethod of claim 113, wherein the pump radiation source is a flash lamp.125. The method of claim 113, wherein said delivering the laser lightcomprises transmitting the laser light through an optical fiber. 126.The method of claim 113, further comprising Q-switching the laser toproduce a train of micropulses.
 127. The method of claim 113, whereinsaid light is absorbed substantially completely by the tissue withinabout 1 mm of the surface, and has average irradiance in the treatmentarea greater than 10 kiloWatts/cm² in a spot size at least about 0.05mm².
 128. The method of claim 113, wherein said light is absorbedsubstantially completely by the tissue within about 1 mm of the surface,and has average irradiance in the treatment area greater than 10kiloWatts/cm² in a spot size between about 0.1 and 0.8 mm² in thetreatment area.
 129. The method of claim 113, wherein said light has anirradiance of at least 30 kiloWatts/cm² in the treatment area in a spotsize at least about 0.05 mm².
 130. The method of claim 113, wherein thelight has a wavelength and has irradiance in the treatment areasufficient to cause vaporization of a substantially greater volume ofsaid tissue than a volume of residual coagulated tissue caused by thelaser radiation.
 131. The method of claim 113, wherein said tissuecomprises uterine tissue, and said treatment is for a gynecologicalcondition selected from leiomyoma uteri, rhabdomyoma, endometriosis,endometrial hyperplasia, endometrial cysts, endometrial polyps,menorrhagia, uterine septa, intrauterine adhesions, or cervicalintraepithelial neoplasia.